A rotor drive of an open-end spinning device is known from DE 10 2006 053 734 A1. The rotor drive drives a shaft and a spinning rotor arranged thereon. The shaft is a part of a traveler of the rotor drive and is magnetically supported on both sides of the rotor drive. The support takes place by means of two permanent magnet rings and a defined energizable magnetic bearing coil. Such elements and an inductive sensor are used to control the axial position of the spinning rotor, which is free-floating during operation. To be sure, it is possible to, in this manner, determine the axial position of the shaft and thus the spinning rotor with relative accuracy, and to maintain it. However, in doing so, the radial position of the shaft and the spinning rotor move in a relatively large tolerance. However, in order to be able to spin a uniform and uninterrupted thread, in addition to the axial position, the radial position of the spinning rotor is extremely important.
A radial magnetic bearing is known from WO 93/05310 A1. A shaft is arranged between pole arms of a stator, which are surrounded by a coil. The shaft is radially centered and held by a magnetic field between the coils. The bearing system and centering can take place by means of an active control system.